1. Field of the Invention
The present invention relates to an optical signal processing device, an information recording/reproducing apparatus and information recording/reproducing system. More particularly, it relates to an audio and video (AV) sever or the like that records audio and video (AV) data stream in a data storage device through a fiber channel (an optical communication line) and/or reproduces the AV data therefrom.
2. Description of Related Art
Recently, the AV server has been often used in a broadcast station, an audio and video information distribution system or the like when editing any audio and video information. The AV server has a data recording/reproducing apparatus, a data storage device and the like. The data recording/reproducing apparatus encodes and compresses any audio and video information according to a predetermined data compression standard when recording the data. Additional information such as header information is added to the coded and compressed audio and video data, thereby producing a data stream. The data recording/reproducing apparatus is connected to the data storage device through an optical communication line (hereinafter referred to as “fiber channel”), in order to enable the data stream to be transmitted at high speeds. The data storage device stores the data stream with a predetermined data format.
The data recording/reproducing apparatus reads the data stream out of the data storage device when reproducing the data, to decode and decompress the data stream. Any decoded and decompressed audio and video data is used as audio and video information. The data recording/reproducing apparatus transmits such the audio and video information to a monitor.
If plural data recording/reproducing apparatuses (originators) are connected to one data storage device in a data recording/reproducing system using such the data storage device, an arbitrated loop topology connection or a fabric topology connection has been often adopted. When the arbitrated loop topology connection is used, a fiber channel hub is used or a physical loop is formed with a transmission line without using any fiber channel hub.
FIGS. 1A and 1B show data recording/reproducing systems 61, 62 relative to related art. Each of the data recording/reproducing systems 61, 62 use the arbitrated loop topology connection.
The data recording/reproducing system 61 shown in FIG. 1A has data recording/reproducing apparatuses 201, 202, a data storage device 301, and a fiber channel hub 601. The fiber channel hub 601 has two ports at its data recording/reproducing side and is connected to the two data recording/reproducing apparatuses 201, 202 through the ports. The fiber channel hub 601 also has a port at its data storage side and is connected to the data storage device 301 through the port.
The data recording/reproducing system 62 shown in FIG. 1B has data recording/reproducing apparatuses 201, 202 and a data storage device 301. In the data recording/reproducing system 62 shown in FIG. 1B, a physical loop is formed with a transmission line without using any fiber channel hub. In this loop, the data recording/reproducing apparatus 201 is connected to the recording/reproducing apparatuses 202 as well as the data recording/reproducing apparatuses 201, 202 are connected to the data storage device 301.
FIGS. 2A and 2B show data recording/reproducing systems 63, 64 relative to related art. Each of the data recording/reproducing systems 63, 64 use the fabric topology connection.
The data recording/reproducing system 63 shown in FIG. 2A has data recording/reproducing apparatuses 201, 202, a data storage device 301, and a fiber channel switch 602. The fiber channel switch 602 has a port at its data storage side and is connected to the data storage device 301 through the port. The fiber channel switch 602 also has two ports at its data recording/reproducing side and is connected to the two data recording/reproducing apparatuses 201, 202 through the ports.
The data recording/reproducing system 64 shown in FIG. 2B has a data recording/reproducing apparatus 201, data storage devices 301, 302, and a fiber channel switch 602′. The fiber channel switch 602′ has two ports at its data storage side and is connected to the two data storage devices 301, 302 through the ports. The fiber channel switch 602′ has a port at its data recording/reproducing side and is connected to the data recording/reproducing apparatus 201 through the port.
FIGS. 3A and 3B show data recording/reproducing systems 65, 66 relative to related art. The data recording/reproducing systems 65, 65 use the arbitrated loop topology connection.
The data recording/reproducing system 65 shown in FIG. 3A has a data recording/reproducing apparatus 201, two data storage devices 301, 302, and a fiber channel hub 601′. The fiber channel hub 601′ has two ports at its data storage side and is connected to the data storage devices 301, 302 through the ports. The fiber channel hub 601′ also has a port at its data recording/reproducing side and is connected to the data recording/reproducing apparatus 201 through the port.
The data recording/reproducing system 66 shown in FIG. 3B has a data recording/reproducing apparatus 201 and data storage devices 301, 302. In the data recording/reproducing system 66 shown in FIG. 3B, a physical loop is formed with a transmission line without using any fiber channel hub. In this loop, the data recording/reproducing apparatus 201 is connected to the two data storage devices 301, 302 as well as the data storage device 301 is connected to the data storage device 302.
Such the data recording/reproducing system may have a tape library device (Japanese Patent Application Publication No.2004-265548). The tape library device has a host computer, a tape library, and a fiber channel switch positioned between the host computer and the tape library. At upper hierarchy of the fiber channel switch, the host computer is connected to the fiber channel switch through the fiber channel while at lower hierarchy of the fiber channel switch, two kinds of fiber channel drivers are connected to the fiber channel switch through the fiber channel, in order to allows the fiber channel drivers to be exchanged and used without rebooting the host computer.